Tank support unit with sealing valve

The tank connecting piece unit (100) has tank connecting piece (142) that is configured to predetermined maximum pressure that is greater than permissible operating pressure of pressure accumulator system in vehicle. A shut-off valve (120) is arranged in through-flow path (140) between tank connecting piece and outlet region of tank connecting piece unit. The shut-off valve is configured to prevent an increase in pressure of pressure accumulator system beyond permissible operating pressure.